Relative bearing and target-angle trainer



July 11, 1950 c, HEERDINK 2,514,392

RELATIVE BEARING AND TARGET-ANGLE TRAINER Filed Dec. 10, 1946 IN VEN TOR.

Roe/5R r C. HEERD/NK A TTOENE Y Patented July 11, 1950 2,514, 392 RELATIVE BEARING AN D TARGET-ANGLE TRAINER Robert Charles Heerdink, Los Angeles, Calif.

Application December 10,- 1946, Serial N 0. 715,237

(Granted under the act or March 3', 1 883,:as

amended April 30, 1928; 370' 0.. G. 757):

Claims.

This invention relates to training devices and in particular to a relative-bearing and targetangl trainer.

An object of this invention is to provide, an apparatus for elementary instruction in estimating target angles and bearings.

Further objects and advantages of this invention, as well as its construction, arrangement, and operation, will be apparent from the accompanying drawing and the following detailed description thereof. In the drawing Fig. 1 is a view in perspective illustrating one practical, embodiment of this invention, and

Fig: 2 is a cross-sectional plan, taken along the line 2-2 of Fig. 1.

A relative-bearing and target-angle trainer embodying the present invention is illustrated'in thedrawing and'isgenerallydesignated II. The trainer It comprises a light containing box or cas I2, the front face of which has a plurality of circular holes or openings which are covered by the closures or discs I3 and I4. Ship models I5 and I5 are attached to the respective closures I3 and Id at the centers of their faces exteriorly of the box I2. The discs I3 and I4 are marked with indicia 30 comprising 360 bearing circles corresponding with the respective ship models I5 and I6, the bearing circles 30 each being graduated in divisions of 5 or other suitable increments of angles. Each of the ship models I5 and I6, and respectively each bearing circles of indicia '30, are positioned on discs 13 and I4 for the bows of the ships to be each at th conventional 000 heading.

Discs I3 and I4 may be of a translucent material such as glass, plastic, or the like, and may be painted black with the bearing-circle markings 30 scratched into the paint to permit light to pass through the markings only. The ship models I5 and I6 are readily visible on the faces of the discs I3 and I4 that are exterior of the box I2 under ordinary light conditions in the room where the device is used. The observer sees the two ship models I5 and It side by side on a field comprising the face of box [2 that embodies discs I3 and I4. Th bearing circles 30 on discs I 3 and I4 are obscured except when case I2 is illuminated from within. Colored filters 24 are placed over bearing circles I 3 and [4 to completely obscure the indicia 30 from view, which are therefore totally invisible to a student facing the box I2, who is able nevertheless to see the ship models I5 and I6 through the filters 24.

The apparatus for illuminating the indicia 30 of the bearing circles, and the apparatus for turn- 2 ing the closures or discsl3 and P4, as shown in Fig. 2.

Discs I3 and I4 are attached to respective-shafts IT and Is by means of flanges I9. A mechanism is provided to rotate discs I3 and I 4, suchas, for example, an electric motor 20 gearedto shaft I! to drive disc I3, and a chain and sprocket 2| to drive shaft I8 and disc I4 carried thereby when shaft I! with disc I3 rotates. The discs I3 and I4 therefore constitute rotary'dials; Topermit one motor 28 to give a wide variety of bearing and target-angle combinations, the sprocket wheels on shafts II and I8 are of different diameters. For example, by using an eight-to-one fractional'gear ratio, disc I3 will make eight revolutions to one revolution of disc I I. The model ships I5 and I6 are mounted on the ends of shafts I1 and} I8; which extend through discs I3 and I I'so that-ships i5 and! 6 rotate with discs I3a-nd I *4". The-indicia 3i! of the bearing circles are illuminated from behind the discs I3 and I4 by a number of lamps 22 within the box I 2 which are supplied from any suitable electrical source. Both the illumination by the lamps 22 and operation of the motor 20 ar remotely controlled by push button switches 23 shown in Fig. 1. To change the relative orientation of the ship models I5 and I6, the motor push button of 23 is depressed until motor 20 turns dials I3 and I 4 to the desired positions. When it is desired to show the markings 30 of the bearing circles, the illumination push button of 23 for the lamps 22 is depressed.

This trainer is adapted to teach the basic principles of estimation of relative bearings and target angles and for elementary drills in estimation of relative bearings and target angles.

The instructor operates the switch 23 for controlling the motor 20 to rotate the discs I3 and I4 until the ship models I5 and I6 assume a predetermined desired relative orientation. Students are then requested to state, with reference to one of the shipv models l5 or I 6 as the simulated ship of observation, what the relative-bearing and target-angle of the other ship is at the given setting. The instructor now operates the switch 23 that turns on the lights 22, rendering the bearingcircle markings of the discs I3 and I4 visible to the students, and enabling the students to determine the accuracy of their estimates of relativebearing and target-angle.

The trainer can be made more readily portable by having the dials l3 and I4 manually operated and the illumination supplied by lights operated by batteries enclosed in case l2.

It is to be understood that various modifications and changes may be made in this invention without departing from the spirit and scope thereof as set forth in the appended claims.

The invention described herein may be manufactured and used by or for th Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. In apparatus for teaching estimation of relative bearings and target angles, a plurality of dials positioned to view their faces side by side, a ship model on the face of each dial and each dial comprising indicia of a bearing circle disposed on the dial in conformance with the position of the ship model thereon, an illuminating system and a control therefore operable to selectively make the indicia visible and to obscure the indicia while the ship models remain visible, and means to rotate the several dials into selectively different relative orientations of their respective ship models.

2. In apparatus as defined in claim 1, the rotating means comprising a motor and a drive from the motor to the dials including a fractional gear ratio between dials.

3. In apparatus for teaching estimation of relative bearings and target angles, a light containing box having a plurality of circular openings in one face thereof, an opaque closure for each box opening comprising a dial, a ship model disposed at the center of each dial exteriorly of the box, each dial comprising translucent indicia of a bearing circle disposed on the dial in conformance with the position of the ship model thereon, an illuminating system inside the box and a control therefore operable to selectively illuminate and darken the interior of the box behind the dials, and means to rotate the several dials into selectively different relative orientations of their re spective models.

4. In apparatus as defined in claim 3, the dials with the exterior of the box and the ship models being colored contrastingly, a light filter over each of the dials and its ship model that obscures the indicia completely but not the ship models when the interior of the box is darkened.

5. In apparatus for teaching estimation of relative bearings and target angles, a light containing box having a plurality of circular openings in one face thereof, an opaque closure for each box opening, comprising a dial, a ship model disposed at the center of each dial exteriorly of the box, each dial comprising translucent indicia of a bearing circle disposed on the dial in conformance with the position of the ship model thereon, mechanism for rotating the dials on their axes comprising an electrical motor and a drive from th motor to the several dials and between the dials, the drive between dials having a fractional gear ratio, an electrical illuminating system inside the box and a control therefore operable to selectively illuminate and darken the interior of the box behind the dials, and a control for operating the dial rotating mechanism at will.

ROBERT CHARLES HEERDINK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,463,470 Johnson July 31, 1923 2,045,619 Smith June 30, 1936 2,132,476 En Holm Oct. 11, 1938 2,166,864 Gelardin July 18, 1939 2,222,519 Schwarz Nov. 19, 1940 

